Seismogenic Fault Reactivation in Western Central Africa: Insights from Regional Stress Analyses
| dc.contributor.author | Nkodia, H.M. | |
| dc.contributor.author | Miyouna, T. | |
| dc.contributor.author | Kolawole, F. | |
| dc.contributor.author | Boudzoumou, F. | |
| dc.contributor.author | Loemba, A.P.R | |
| dc.contributor.author | Bazebizomba, N.C.T | |
| dc.contributor.author | Delvaux, D. | |
| dc.coverage.spatial | Africa - Central | |
| dc.coverage.spatial | Congo | |
| dc.coverage.spatial | Congo, The Democratic Republic of the | |
| dc.coverage.spatial | Cameroon | |
| dc.coverage.spatial | Africa - Western | |
| dc.coverage.temporal | Cenozoic | |
| dc.date | 2022 | |
| dc.date.accessioned | 2024-03-14T13:26:34Z | |
| dc.date.available | 2024-03-14T13:26:34Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/12977 | |
| dc.description | The onshore continental margins of western Central Africa have been hosting potentially damaging earthquake events for decades; yet, the links between the seismicity, the contemporary stress field, and pre-existing faults are not well understood. Here, we analyze the regional stress fields along the coastal margin and interior cratonic areas using earthquake focal mechanisms, map and characterize the detailed structure of preexisting fault systems in outcrops, and asses the reactivation potential of the mapped structures. Our results show that the earthquakes originate under a transpressive stress regime with a horizontal maximum principal compressive stress (σ1) that is oriented NNE-SSW. We show that regional stresses acting on offshore oceanic fracture zones are compatible with those acting along the onshore areas of the continental margin. Field observations reveal the presence of large fault systems that deform both the Precambrian basement and Phanerozoic sedimentary sequences, with widespread hydrothermal alterations of calcite veining, quartz veining, and palygorskite mineralization along the fault zones. Along the margin, the preexisting NNE-, NNW-, and N-S -trending strike-slip faults and normal faults show a high slip tendency (60 100 %), whereas in the cratonic interior, the NW-and N-S -trending thrust faults are the most likely to reactivate. We argue that favorable orientation of the preexisting faults and potentially, their hydrothermal alteration products, define the susceptibility of the faults to seismic reactivation. We propose that possible stress propagation into the near-shore and onshore tip zones of oceanic fracture zones may be driving stress loading on pre-stressed fault systems onshore. | |
| dc.language | eng | |
| dc.title | Seismogenic Fault Reactivation in Western Central Africa: Insights from Regional Stress Analyses | |
| dc.type | Article | |
| dc.subject.frascati | Earth and related Environmental sciences | |
| dc.audience | Scientific | |
| dc.subject.free | Geodynamics and mineral resources | |
| dc.source.title | Geochemistry, Geophysics, Geosystems | |
| dc.source.volume | In press | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.1029/2022GC010377 | |
| dc.identifier.url | https://www.essoar.org/doi/10.1002/essoar.10510563.2 | |
| dc.identifier.rmca | 6279 |